Just as Miles Davis' Kind of Blue was one of those jazz albums you saw in the collections of people who otherwise didn't listen to jazz, Glenn Gould's 1955 LP of Bach's Goldberg Variations stuck out in record collections otherwise devoid of classical music.

Gould's Goldbergs introduced millions of Americans to a breathtakingly new sonic landscape. Davis achieved his unique sound by introducing ancient musical modes to the world of jazz. Gould, on the other hand, unlocked the hitherto unknown emotional depths of Bach's powerfully mathematical musical intellect.

In short, Glenn Gould gave Bach soul — and Bach gave Gould great source material. Picking five great recordings of the Goldberg Variations these days without mentioning Gould is a little like leaving Sgt. Pepper's Lonely Hearts Club Band out of a list of greatest rock albums of all time.

Love Gould or hate him, without him we wouldn't be discussing this — or any other — list of recordings of what has been called the longest, most ambitious and most important solo keyboard work written before Beethoven. As you ponder that, consider what else Gould wrought: His was the first prominent album devoted to Bach's magisterial 32-movement work. The tally of recordings today is no fewer than 193. So, leaving Gould to his own category, here are some highly personal and subjective recommendations.